Smart cards are used as bankcards, ID cards, telephone cards and the like. They are based upon the use of an electromagnetic coupling (either by direct physical contact or by electromagnetic waves) between a smart card's electronic components and a card reader, pickup head or other appropriate electronic signal receiving device such as those employed in an ATM. Because these cards are so widely used to effect very valuable and/or otherwise important transactions, they are the frequent subject of fraudulent activities. These fraudulent activities often involve physically tampering with a smart card's electronic components. For example, their computer chips or other electronic components are removed from a valid smart card and physically transferred to a fraudulent card in order to gain money, unauthorized access, unauthorized information, etc.
Smart cards are usually made by assembling several layers of plastic sheets in a sandwich array. In the case of so-called "contact" type smart cards at least one face of the smart card has an opening in which an electronic signal sensing component such as a strip-like sensor, computer chip, module or "pickup head" reside(s). The electronic signal sensing component comes into direct physical contact with an electrically cooperating component of a machine (e.g., an ATM machine, credit card transaction machine, a personal identity verification machine, telephone, etc.) in which the contact type smart card is employed. Many contact type smart cards have all of their electrical components (e.g., their electronic signal sensing device and their computer chip assembled) in a unified module that is glued in an open cavity in a face of the card. By way of distinction, so-called "contactless" smart cards communicate with the machines in which they are employed by means of a radio wave-receiving antenna that is embedded in the interior of the contactless smart card. Hence, there is no physical contact between the card's electronic signal sensing component(s) and the user machine's signal sensing component. Some smart cards operate in hybrid, contact/contactless, modes of operation.
Applicant's invention may be used with any of these three types of smart card; but for reasons hereinafter more fully explained, it is more particularly concerned with "contact" type smart cards and/or the methods employed to manufacture them. The methods by which prior art smart cards have been manufactured have varied considerably. For example, U.S. Pat. No. 5,272,374 discloses an integrated chip-employing smart card comprising a card board having a first and a second major surface and a semiconductor module having an electrode terminal face. The semiconductor module is mounted in the card board such that the electrode terminal face is left exposed in the first major surface of the card board.
U.S. Pat. No. 5,311,396 teaches a portable and connectable chip-based smart card system having one or more chips integrated into a package. The electronic component is mounted on the upper surface of metal contacts. A lower surface has metal contacts that constitute a connector of the system. Each of the metal contacts of the upper face is connected to, and faces, a metal contact of the lower surface, and vice versa. In a second embodiment of this invention, the electronic component is surface mounted on an upper surface of the metal contacts in a manner such that the lower surface of these contacts forms the connector.
U.S. Pat. No. 5,486,687 teaches a memory card having several integrated circuits for personal computers. These memory cards serve as a large capacity mass memory for replacing floppy disks and other exchangeable magnetic supports. They are provided with a plug-in connector at the end of the card and can be inserted in the reader in a prescribed manner, e.g., in accordance with PCMCIA standards. According to one aspect of this invention, a flush contact chip card memory is formed by such a plug-in card. To this end, the card has a supplementary connector with flush contacts on its principal face. The resulting reader is transportable. Its application software can be stored in the card and can be installed in any random microcomputer equipped with a PCMCIA reader.
All of these prior art methods for making contact smart cards are to some degree concerned with properly positioning and fixing the electronic signal sensing component module or assembly inside the smart card in such a way that they present a flat surface on or substantially flush with the card's face surface (or its obverse surface). Unfortunately, this proximity of the signal sensing component to the face surface (or its obverse) of contact smart cards presents an opportunity for tampering with, and fraudulent use of, such cards.